Porifera and Placozoa 9/1/2005 Phylum Porifera PoriferaPorifera and and Placozoa Placozoa 1 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Echinodermata Uniramia Crustacea Vertebrata Chelicerata Nematoda Protochordata Priapulida Kinorhyncha Loricifera Hemichordata Annelida Mollusca Bryozoa Apicomplexa Actinopoda Brachiopoda Phoronida Ciliophora Platyhelminthes Euglenozoa Rotifera Rhizopoda Cnidaria Granuloreticulosa Porifera 2 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Poriferan diversity PoriferaPorifera and and Placozoa Placozoa 3 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Digital Zoology © The McGraw-Hill Companies, Inc. 1 Porifera and Placozoa 9/1/2005 Poriferan diversity PoriferaPorifera and and Placozoa Placozoa 4 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Poriferan diversity PoriferaPorifera and and Placozoa Placozoa 5 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Poriferan diversity PoriferaPorifera and and Placozoa Placozoa 6 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Digital Zoology © The McGraw-Hill Companies, Inc. 2 Porifera and Placozoa 9/1/2005 Poriferan characteristics z 98% marine, 2% freshwater z Among the first of multicellular (Metazoan) animals z Individual cells subordinate to the “organism” z Differentiation of cell types for division of labor – Choanocytes (food collection, reproduction) – Pinacocytes (outer protection) – Porocytes (regulate water inflow, guard against intruders) – Amebocytes or Archeocytes (food digestion, storage, waste disposal, sundry other functions) – Sclerocytes (secrete spicules) – Spongocytes (secrete spongin) z Non-cellular matrix uniting organism: – Spongin protein – Spicules (Ca, Si) PoriferaPorifera and and Placozoa Placozoa 7 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Things sponges do not have z Tissues (nor organs, etc) z Regular symmetry z Extracellular digestion z Sense organs (or nervous system) z Mobility PoriferaPorifera and and Placozoa Placozoa 8 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Sponge structure Osculum Spongocoel Inhalant pore PoriferaPorifera and and Placozoa Placozoa 9 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Digital Zoology © The McGraw-Hill Companies, Inc. 3 Porifera and Placozoa 9/1/2005 Cells organised into layers (not yet “tissues”) Pinacoderm Mesohyl (non-cellular) Choanoderm PoriferaPorifera and and Placozoa Placozoa 10 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Pinacocyte (form pinacoderm) PoriferaPorifera and and Placozoa Placozoa 11 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Porocyte Dermal ostia PoriferaPorifera and and Placozoa Placozoa 12 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Digital Zoology © The McGraw-Hill Companies, Inc. 4 Porifera and Placozoa 9/1/2005 Choanocytes PoriferaPorifera and and Placozoa Placozoa 13 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Sclerocytes PoriferaPorifera and and Placozoa Placozoa 14 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Amebocytes PoriferaPorifera and and Placozoa Placozoa 15 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Digital Zoology © The McGraw-Hill Companies, Inc. 5 Porifera and Placozoa 9/1/2005 Internal organisation z 3 basic types – Asconoid – Syconoid – Leuconoid PoriferaPorifera and and Placozoa Placozoa 16 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Asconoid sponges Osculum Spongocoel Water flow Ostium Porocyte PoriferaPorifera and and Placozoa Placozoa 17 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Syconoid sponge Osculum Spongocoel Choanocyte PoriferaPorifera and and Placozoa Placozoa 18 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Digital Zoology © The McGraw-Hill Companies, Inc. 6 Porifera and Placozoa 9/1/2005 Leuconoid sponge Osculum Excurrent canal Choanocyte chamber PoriferaPorifera and and Placozoa Placozoa 19 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Feeding and Digestion Choanocyte flagellum Microvillar collar Food vacuole Amebocyte in the mesohyl PoriferaPorifera and and Placozoa Placozoa 20 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Poriferan reproduction Micropyle Asexual Asexual Spicule Budding Fragmentation Gemmule formation Sexual Many hermaphroditic PoriferaPorifera and and Placozoa Placozoa 21 Digital Zoology © The McGraw-Hill Companies, Inc. 13:48 Digital Zoology © The McGraw-Hill Companies, Inc. 7.